Indoor Incense Triggers Lung Cell Inflammation, Study Shows

Researchers identified and measured particles and gases released from two kinds of incense widely used in homes in the United Arab Emirates. Human lung cells were placed in the chamber while the incense was burned.

The inflammatory response in the lung cells exposed to the incense was similar to that seen in lung cells exposed to cigarette smoke, according to the study in the August issue of the journal Science of the Total Environment.

Both types of incense -- Oudh and Bahkoor -- are made with agarwood, which is taken from trees that develop an aromatic smell in response to fungal infection. Bahkoor has a number of additives, including sandalwood tree resin, essential oils and other substances, the University of North Carolina at Chapel Hill researchers explained.

The investigators found that both types of incense emitted pollutants at significant levels, including carbon monoxide, formaldehyde and nitrogen oxides. Therefore, people should open a window or door or take other steps to improve ventilation when burning incense, the study authors suggested.

Previous research by one of the study co-authors, Karin Yeatts, and her colleagues linked incense smoke with a number of health problems, such as: irritation of the eyes, nose, throat and skin; asthma and other respiratory symptoms; headaches; worsening of cardiovascular disease; and changes in lung-cell structure.

Indoor air pollution is an international health concern. The World Health Organization estimates that more than 1 million people a year die from respiratory diseases, most of which are due to exposure to pollutants from cook stoves and open hearths. Burning incense releases similar pollutants.